Pressurized gas sampling container

ABSTRACT

A gas sampling container ( 15 ) capable of obtaining, isolating and transporting samples of gas or other fluid under pressure form. The container ( 15 ) further exhibits a plurality of simple, reliable, inexpensive, self sealing, valves ( 2 ) which allow introduction, flow through and exit of the gas sample. The container ( 15 ) is suitable for taking discrete or serial samples from a gas or fluid flow source and is especially suited for use in automated sampling apparatus. These containers are acceptable for shipment of compressed flammable gases under the regulatory structures of many countries.

This application is the National Stage of International ApplicationPCT/USO4/38636 filed 12 Nov. 2004 which in turn claimed the benefit ofU.S. Provisional Application No. 60/519,410 filed 12 Nov. 2003.

TECHNICAL FIELD

This pressurized gas sampling container relates to the collection,transportation and analysis of gas samples which may be required invarious scientific, environmental and resource contexts. As an example,in oil and natural gas exploration, drilling, recovery and storage,periodic sampling of recovered gases and fluid are required forsubsequent analysis. In the oil industry, “mud” is a colloquial term fora thick chemical composition that is pumped into drills as theypenetrate the substrate. This “mud” is returned to the surface andcontains gases that are released from the rock as the drill penetrates.Significant data is acquired from the analysis of these gases.

BACKGROUND ART

International Publication Number WO 01/79805 A1 discloses a nonpressurized sampling container in conjunction with a sampling apparatus.This system and non-pressurized sampling container is widely used in thegas sampling industry specifically, in the mud gas sampling sector. U.S.Pat. No. 5,116,330 to Spencer provided for a sample extraction systemwith a sampling container and valves. Such a sampling system requiresthe interruption of the fluid flow as sampling containers are exchanged.Further, extraction of the sample from the sampling container wasaccomplished by “bleeding” the container, a technique which relies ongravity and is suitable for fluids in a liquid rather than a gaseousstate. Although less common today, the gas sampling industry utilizessampling bags which have the obvious problems of fragility, occupying asignificant volume when being shipped and the inability to contain gasor fluid under any significant pressure.

DISCLOSURE OF THE INVENTION

This pressurized tube facilitates the recovery and transportation of gassamples. This pressurized sampling container, made from aluminum will beusable at pressures up to 270 pounds per square inch (1860 kPa),however, other materials such as steel or plastic, other polymers,carbon fiber and other metals may allow higher pressures. There areseveral advantages in utilizing pressurized gas sampling containers.High pressure containers are very expensive and with valves and endcaps, can exceed $200.00 per unit. The present invention will retail atapproximately $25.00 per unit. More fundamentally, there are currentlyno readily available low pressure sampling containers on the market withthe advantage of flow through gas collection. These types of containersare difficult to purge and thus samples collected in them are generallycontaminated with whatever materials were previously in the container.

Further, by compressing the gas, the amount of sample that can becollected is several times larger than with the non-compressed gassampling containers or tubes. For example, at 150 psi, the amount ofsample is actually 11 times as much as a non compressed sample in thesame size container. This larger sample size allows additional analysesto be carried out that could not be done on the non-compressed gassampling containers or tubes. It is anticipated that this container willmeet or exceed the United States Department of Transportationrequirements for the shipping of compressed gases. Specifically, It isacceptable for shipment of compressed flammable gases under the USDepartment of Transportation classification UN2037, RECEPTACLES, SMALL,CONTAINING GAS. It is also anticipated the container will meet or exceedsimilar standards in other countries.

The use of low pressure sampling containers will also simplify shipping.With the currently used non-compressed gas sampling containers or tubes,depending on size, a maximum of 8 per box could be shipped on passengeraircraft and, according to the regulations of the International AirTransport Association (IATA), up to 40 per box could be shipped oncargo-only aircraft. This is a significant disadvantage because manyareas of the world do not have cargo-only aircraft service. Because theprojects for which the gas sampling containers or tubes are used involvecollection of as many as 200 to 300 samples, shipping in small groups isvery inefficient and expensive. This has resulted in some samples beingsent by ship with a resultant delivery times of several months. Fornon-compressed gases, shipping quantities are given as volumes (1 literfor passenger aircraft, 5 liters for cargo-only aircraft). Forcompressed gases, quantity limitations are by net weight. The inventionis suitable for the transportation of many kinds of gases, however,consider, for example, using the container to ship natural gas samples.Natural gas is mostly methane and generally lighter than air. Thus, thequantity that can be shipped in one outer package, even on passengeraircraft, is so large that it presents no practical limitation. 25, 50,or even 100 of the compressed gas containers per box will meetregulations.

The ability to ship pressurized samples will also simplify samplecollection. Often the lines or apparatus from which gases must becollected is pressurized. An example is the collection of mud gases fromoil and gas well drilling operations. In some cases the sample must bedrawn from a line that is pressurized to 25 or 30 psi. With thenon-compressed gas sampling containers or tubes, it was necessary toreduce the pressure in the container to atmospheric pressure before theycould be shipped. This was a complicating factor and resulted in somesamples actually being shipped improperly.

The invention has valves on both ends which can be opened and closedindependently and which allow the container to be purged by simplyflowing the sample gas through it. As long as the quantity of sample gasavailable is not limiting, the container does not have to be evacuatedprior to use. The valves are simple, reliable, self sealing andinexpensive and the invention is readily adaptable for use withautomated sample collection and analysis systems.

FIG. 1 is an embodiment of a sample container fashioned from a cylinderhaving a closed end and a cap disposed over an opened end as opposed tocontainer fashioned from a cylinder having two opened ends. FIG. 1 showsa cross section of a cylinder (15) having a closed end (10), which isperforated by circular cylinder aperture (8). An elevation view of theclosed end (10) is seen in FIG. 2, which also exhibits circular aperture(8). Returning to FIG. 1 it is seen that cylinder walls (16) extendtoward an open cylinder end (19). The open cylinder end (19) exhibits arolled lip (18) formed by cylinder wall (16) being formed inward thenoutward to such an extent that cylinder wall (16) touches itself atpoint (17) thus forming the rolled lip (18). Cap (20) is shown in FIG. 1and also in FIG. 3. Cap (20) is cup shaped and of such a diameter thatcap sides (19) communicate with rolled lips (18) yet allows cap bottom(22) to slide within cylinder (15) allowing partially rolled flange (26)to also communicate with rolled lip (18). Partially rolled flange isformed in such a way as to allow its inner curved surface (27) tocommunicate with outer curved surface (28) of rolled lip (18). Seal (25)is annular in shape and rests on the inner curved surface. When cap (20)is fully inserted into cylinder (15), partially rolled flange (26)communicates with seal (25) which, in turn, communicates with rolled lip(18) forming an air or gas tight seal. When partially rolled flange isthen further rolled or crimped, the flange end, is pressed under rolledlip (18) at point (30). This tightly compresses seal (25) allowingcylinder (15) to be so tightly sealed as to allow cylinder (15) tocontain compressed gasses or liquids. Cylinder (15) will be composed ofaluminum, steel or other substance of suitable strength for compressedgasses and liquids. Circular cap aperture (24) is substantially the samediameter as circular cylinder aperture (8). Valve body (2) is insertedthrough circular cylinder aperture (8) such that valve body first end(4) is exterior to cylinder (15) and valve body second end (6) isinterior. Valve body lip (14) causes valve body second end (6) to beretained with cylinder (15) and also allows the compression of seal (12)between valve body lip (14) and cylinder end (10). The valve body issubstantially similar to FIG. 5 and it can be seen that valve body (2)is externally threaded. Valve body (2) will accept washer (3) over valvebody first end (4) and will also accept internally threaded nut (5) suchthat when internally threaded nut (5) is threaded over the externalthreads of valve body (2) it tightens and compresses seal (12) betweenvalve body lip (14) and cylinder end (10) allowing a sufficient seal toretain compressed gasses. A similar valve body is inserted through capcircular aperture (24) with valve body first end (4) exterior tocylinder (15) and valve body second end (6) inside cylinder (15) whencap (20) is inserted into cylinder (15) and resting on rolled lip (28).FIG. 4 illustrates cap (20) inserted through open cylinder end (19) withvalve body (2) in proper position through circular cap aperture (24).FIG. 5 also illustrates an alternative crimping method wherein a portionof the cap wall (23) is expanded into lip (29) such that lip (29)applies pressure under rolled lip (18). This, in turn causes partiallyrolled flange (26) to seat on the upper surface of rolled lip (18)causing seal (25) to be compressed thus sealing the cylinder. Bothillustrated crimping methods may be used independently or inconjunction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view of the sampling container.

FIG. 2 is a plan view of the container closed end.

FIG. 3 is a plan view of the cap.

FIG. 4 is a perspective view of the valve and cap in place within theopen end of the sampling container.

FIG. 5 is a cross section view of the valve body.

FIG. 6 is a cross section view of the plunger valve.

FIG. 7 is a perspective view of the sampling apparatus.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows a cross section of a container (15) having a closed end(10), which is perforated by circular container aperture (8). Anelevation view of closed end (10) is seen in FIG. 2, which also exhibitsaperture 8. Turning again to FIG. 1 it is seen that container walls (16)extend toward open container end (19). The open container end (19)exhibits a rolled lip (18) formed by container wall (16) being formedinward toward the longitudinal midline of the container then outward tosuch an extent that container wall (16) touches itself at point (17)thus forming the rolled lip (18). Cap (20) is shown in FIGS. 1, 3 and 5.Cap (20) is cup shaped and of such a diameter that cap sides (23)communicate with rolled lips (18) yet allows cap bottom (22) to slidewithin container (15) allowing partially rolled flange (26) to alsocommunicate with rolled lip (18). Partially rolled flange (26) is formedin such a way as to allow inner curved surface (27) to communicate withouter curved surface (28) of rolled lip (18). Seal (25) is annular inshape and rests on the inner curved surface (27). When cap (20) is fullyinserted into container (15), partially rolled flange (26) communicateswith seal (25) which, in turn, communicates with rolled lip (18) formingan air or gas tight seal. When partially rolled flange (26) is thenfurther rolled or crimped, the flange end (29A), is pressed under rolledlip (18) at point (30). This tightly compresses seal (25) allowingcontainer (15) to be so tightly sealed as to allow container (15) tocontain compressed gasses or liquids. Container (15) will be composed ofaluminum, steel or other substance of suitable strength for compressedgasses and liquids. Circular cap aperture (24) is substantially the samediameter as circular container aperture (8). First valve (2) is insertedthrough circular container aperture (8) such that valve first end (4) isexterior to container (15) and valve second end (6) is interior. Valvelip (14) causes valve second end (6) to be retained with container (15)and also allows the compression of seal (12) between valve lip (14) andcontainer end (10). Second valve (2A) is substantially similar to FIG.5, as is first valve (2) and it can be seen that valve (2A) exhibitsexternal threads, specifically first external thread (40) and secondexternal thread (41). Returning to FIG. 1 it is seen that first valve(2) will accept washer (3) over valve first end (4) and will also acceptinternally threaded nut (5) such that when internally threaded nut (5)is threaded over the first external thread (40) of valve (2) it tightensand compresses seal (12) between valve lip (14) and container end (10)allowing a sufficient seal to retain compressed gasses. Second valve (2)is inserted through cap aperture (24) with valve first end (4A) exteriorto container (15) and valve second end (6A) inside container (15) whencap (20) is inserted into container (15) and resting on rolled lip (28).FIG. 4 illustrates cap (20) inserted through open container end (19)with second valve (2A) in proper position through circular cap aperture(24). FIG. 4 also illustrates an alternative crimping method wherein aportion of the cap wall (23) is expanded into lip (29) such that lip(29) applies pressure under rolled lip (18). This, in turn causespartially rolled flange 26 to seat on the upper surface of rolled lip(18) causing seal (25) to be compressed thus sealing the container. Bothillustrated crimping method may be used independently or in conjunction.

Turning now to FIG. 5, the first valve (2) is illustrated. It iscomposed of a transverse base (78) and annular section (79). Annularsection (79), which is attached to the transverse base (78), exhibitsexternal thread (40) and second external thread (41). Central bore (110)extends through both transverse base (78) and the annular section (79).The valve first end (4) exhibits both external threads (41) and internalthreads (42) within the central bore (110). The central bore (110)exhibits a conical narrowing, the central bore valve seat section (82).It is here that a plunger-activated valve (85) is seated. Second valve(2A) is configured substantially similar to that of first valve (2).

Turning now to FIG. 6 plunger activated valve (85) is shown. Plungeractivated valve 85 is composed of a valve body 86 having a centralcavity 90. Externally threaded first plunger valve body end 91 has acentral bore 92 and a plurality of apertures 93 that communicate withthe central cavity 90. The second plunger valve body end 94 alsoexhibits a corresponding central bore 95 with an annular space alsocommunicating with the central cavity 90. The exterior of the valve body86 exhibits a conical plunger valve body segment 105. A plunger valvebody gasket 114 is seated around the conical plunger valve body segment105 and substantially corresponds to the shape of the central bore valveseat section 82 shown in FIG. 5. Within the central cavity 90 area firstplunger rod support 96 having a central bore 97 and a plurality ofapertures 98. The first plunger rod support is fixed to the interiorwalls of the central cavity 90. A second plunger rod support 99 also hasa central bore 100 and a plurality of apertures 101. The second plungerrod support 99 is also fixed to the interior walls of the central cavity90. Thus the central bores of the second plunger valve body end 94, thesecond plunger rod support 99, the first plunger rod support 96 and thefirst plunger valve body end 91 all correspond such that plunger 87 canbe disposed through all. Plunger 87 has a first plunger end 103 disposedoutside central cavity 90 and above valve body 86. A second plunger end104 is also disposed outside the central cavity 90 and below valve body86. Plunger 87 also exhibits spring stop 115 fixed to plunger 87 betweenfirst plunger rod support 96 and second plunger rod support 99 but at apoint on plunger 87 where the spring stop 115 communicates with theinterior surface of the first plunger rod support 96 when in a restingposition. The resting position is maintained by spring 89 disposed overthe plunger rod and communicating with spring stop 115 and the secondplunger rod support 99. Fixed to the second plunger end 94 in such amanner as to preclude leakage around the plunger 87 is plunger gasket88. Plunger gasket 88 seals the central bore 95 and annular space 102 ofsecond plunger valve body end 94 by being held against the secondplunger valve body end 94 by the pressure exerted by spring 89 on springstop 115. Now returning to FIG. 5, it can be seen that when secondplunger valve body end 94 of plunger activated valve 85 is inserted intofirst annular section end 80 of first end cap valve body 77, externallythreaded first plunger valve body end 91 may be disposed within theinternal threads of first annular section end 80. Disposition of plungeractivated valve 85 is to such a depth as to press plunger valve bodygasket 114 firmly against central bore valve seat section 82 creating aseal.

When first valve 2 and second valve 2A are inserted within theirrespective apertures, the cap sealed within the sample container, andplunger activated valves are mounted within the valve bodies, the samplecontainer then obtains the ability to seal within it a gas sample. Theplunger activated valves, when fluidly connected to an apparatus capableof depressing the plunger valves yet maintaining a seal (such as thatseen in International Publication Number WO 01/79805 A1), that is aninjection and extraction means, it will result in injection, extractionor flow through of a pressurized gas sample.

FIG. 7 depicts such an apparatus for taking a sample. Frame 740 supportsfirst 705 and second 712 sample containers between fixed chucks 704 and713 and spring-loaded chucks 706 and 711, respectively. Material to besampled is sent to inlet 747, which a connected by a three-way valve 702to both sample containers via associated as conduits shown in thefigure. Another three-way valve 708 leads from both sample containers toa common outlet. Both three-way valves are controlled in tandem byhandle 703, connected to a shaft 709, connecting the both three-wayvalves together, so that inlet flow is sent to a particular samplecontainer supported in the frame; the intermediate position of thehandle closes the two outlets for both valves.

INDUSTRIAL APPLICABILITY

This pressurized gas sampling container finds application in the oil andgas industry and any industry or application in which the discrete orcontinuous sampling of gases or fluids are required in which apressurized sample is desired which needs to be economically anefficiently transported to a location where the sample is removed fortesting.

1. A sampling container, comprising: a body; a closed body endperforated by an aperture having a first self-sealing valve disposedthereacross; an open body end; and a cap having cap aperture and asecond self-sealing valve disposed thereacross, said cap disposed withinsaid open body end and attached thereto in a gas tight seal; said firstand second self-sealing valves each comprises a spring-loaded plungerslidably disposed therein and biasing an end of the plunger against agasket in a normally closed position; said container adapted for beingmounted for fluid collection in a sampling apparatus, said self-sealingvalves being normally closed and being opened by mounting said containerin such apparatus; wherein the sampling apparatus comprises a pluralityof chucks into which said first and said second self-sealing valve maybe disposed creating a gas tight seal, said plurality of chucks capableof opening said first and second self-sealing valves.
 2. The containerof claim 1 wherein said open body end is defined by a rolled lip.
 3. Thecontainer of claim 2 wherein said cap comprises a partially rolledflange and said flange is pressed under said lip to seal the cap to thebody.
 4. The sampling container of claim 2 wherein said cap comprises apartially rolled flange and said flange is crimped onto said lip.
 5. Thesampling container of claim 2 wherein said cap comprises (a) a partiallyrolled flange and (b) a wall having an expanded lip formed therein, saidwall extending into said open end, whereby said cap is sealed to saidbody by compression of said rolled lip between said partially rolledflange and said expanded lip.
 6. The sampling container of claim 1wherein said first and second self-sealing valves disposed coaxially insaid container, and each valve having a slidable plunger biased in anormally closed position.
 7. The sampling container of claim 1 whereinsaid first and second self-sealing valves are opened independently. 8.The sampling container of claim 1 wherein said body is a materialselected from the group consisting of metals, polymers, and carbonfiber.
 9. The sampling container of claim 8 wherein said body comprisessteel or aluminum.
 10. The sampling container of claim 1 housing apressurized sample.